This multicenter, outpatient, double-blind, placebo-controlled, randomized, multiple oral dose study will evaluate the safety and pharmacodynamic responses of growth hormone (GH), insulin-like growth factor I (IGF-I) and IGF binding protein 3 to three different oral dose regimens of GPA-748, a synthetic hexapeptide with GH releasing activity, in GH deficient adults. GPA-748 given orally to healthy volunteers caused a dose-dependent release of GH and was well tolerated.